Spermicide
Sponges are a physical barrier, trapping sperm and preventing their passage through the cervix into the female reproductive system. The spermicide is an important component of pregnancy prevention; each brand offers a different formula.
The Today sponge contains 1,000 milligrams (mg) of nonoxynol-9. Protectaid contains 5,000 mg of the F-5 gel, with three active ingredients (6.25 mg of nonoxynol-9, 6.25 mg of benzalkonium chloride, and 25 mg of sodium cholate). Pharmatex contains 60 mg of benzalkonium chloride.
Read more about this topic: Contraceptive Sponge